How Much You Clap Depends On Who's In The Audience, Not On The Stage

How do you decide when to start clapping after a virtuoso
performance? And when do you stop?

New research finds the answer lies in
what other people around you are doing. The louder the
applause — indicating that more people are clapping — the more
likely you are to join in, according to the study published today
(June 18) in the Journal of the Royal Society Interface.

"Behaviors can spread through a group a bit like a disease," said
Richard Mann, a mathematics researcher at Uppsala University in
Sweden. "They hop from person to person until most of the room is
infected."

Contagious clapping

Mann and his colleagues had previously researched how
birds move in flocks and fish swim in schools. The applause
study was a way to examine a similarly simple group behavior in
humans.

To get people clapping, the scientists assembled groups of 13 to
20 students into audiences and had them watch a brief
presentation by another student. The audience was told the
presenter was a volunteer, so they should give that person a hand
after the talk. Unbeknownst to the participants, however, the
researchers were filming them, recording exactly when they
started and stopped clapping.

The experiment was repeated six times, with the same presentation
but different audiences.

The main discovery, Mann told LiveScience, is that neither your
immediate neighbors' behavior nor the quality of the presentation
determines the spread of clapping. Instead, clapping built upon
itself.

"People started to pick up the rate at which they clapped when
they heard more and more people in the room clapping," Mann said.

On average, the first person started clapping 2.1 seconds after
the presentation ended, with the whole room joining in by 2.9
seconds. The applause (from start to finish) lasted an average of
6.1 seconds.

"There wasn't a
tipping point," at which a crucial number of people started
clapping so everyone joined in, Mann said. "The social pressure
to clap just increased in proportion to the number of people who
had already done so."

How social behavior spreads

Clapping stopped in a similar way, with people following the
crowd to cease their applause, Mann said. But the length of
clapping varied widely, because someone in the group had to be
the first to decide to stop. This leader's cessation of clapping
triggered a cascade of more and more people stopping, too.

The clapping pattern roughly fits a disease model, in which the
greater the number of people who have a cold, the more likely you
are to get it, Mann said. The study confirms the disease-like
spread of behaviors, he said, which scientists have long
speculated over but haven't been able to test experimentally
before.

Ultimately, Mann said, the goal is to expand the research to more
complex behaviors. Scientists could track
social media chatter, for example, to determine which cues
trigger people to join a social protest movement. Close friends
might have a big influence, Mann said, or perhaps the general
amount of chatter in a wider social network is the determining
factor.

"With clapping, there is very little consequence when you get it
wrong, whereas joining a protest movement, especially in a
repressive country, you need to be sure you're doing the right
thing," Mann said.